One thing to keep in mind with this setting is the speed of the boat.....

The "Chart View" in a a HB unit defaults to "North Up" when the GPS receiver does see movement...

If the boat speed slows to below 0.6mph, the "boat shaped" icon on the chart view changes into the "Donut"...(indicating the unit does not recognize movement)...

If the unit is set to "Course Up" and the boat slows to below 0.6mph....the chart will default to "North Up" ...no matter which way the boat was moving before the icon changed to the "Donut".....

For example...if the unit is set to "Course Up" and the boat is traveling South....."South" will be at the top of the screen....
Now, if the boat slows to below 0.6mph...the chart will "spin" around to default at "North Up' on the chart....

To keep the chart from continually spinning at speeds below 0.6mph...it may be best to set the unit to "North Up"...

Rickie